Wireless telephones, such as mobile/cellular telephones, cordless telephones, and other consumer audio devices, such as mp3 players, are in widespread use. Performance of such devices with respect to intelligibility can be improved by providing noise canceling using a microphone to measure ambient acoustic events and then using signal processing to insert an anti-noise signal into the output of the device to cancel the ambient acoustic events.
In an adaptive noise cancellation system, it is often desirable for the system to be fully adaptive such that a maximum noise cancellation effect is provided to a user at all times. However, when an adaptive noise cancellation system is adapting, it consumes more power than when it is not adapting. Therefore, it may be desirable to have a system that can determine when adaptation is needed, and only adapt during such times in order to reduce power consumption.